If you haven't figured out by now that pressing the Windows Key + L on your keyboard will lock your screen, don't have a keyboard with a Windows Key (don't be ashamed - I'm rocking it old school too, with a Micron keyboard vintage 1995) or just want to impress your friends with your level of geekery and security, check out the USB Wireless PC Lock. This USB drive, which retails at about $37, plugs into any USB port and includes a wireless receiver that talks to a button-sized transmitter you can keep in your pocket. If you get more than a few feet away from the computer, the drive automatically locks the Windows desktop and requires either the presence of the transmitter or a password to a let a user back in.

The unit sports 2,000 hours of battery life, but there's no mention of what you do after the battery dies - or whether your security can be compromised if someone snatches the USB drive out of your computer.

Via Coolest Gadgets